Cellulose derivatives confer many important benefits to personal care compositions, including, depending on which cellulose derivative is selected, thickening, sensorial benefits, foam enhancement, SPF boost, and many others. One common problem among the water-soluble cellulose derivatives is getting them in solution, which requires sufficient dispersion and hydration. Dispersion refers to spreading of particles or groups of polymer chains throughout a solution. Hydration refers to loosening of the polymer chains and expansion of their hydrodynamic volume (and corresponding viscosity buildup). If dispersion is poor, or if hydration outpaces dispersion, hydrated polymer can swell and isolate relatively dry, non-hydrated polymer from the solution, forming lumps. Desirable dispersion and hydration are normally characterized by little to no lump formation and a rapid viscosity build up over time, respectively.
Accordingly, it has long been a goal in the industry to produce water-soluble cellulose derivatives which are readily dispersible and hydrate quickly in aqueous solutions, more particularly at room temperature. To this end, those skilled in the art have added wetting agents or other adjuvants to water-soluble cellulose derivatives to improve dispersion and hydration, the most widely adopted technique being treatment with glyoxal, or glyoxal and sodium tetraborate. However, like many dialdehydes, glyoxal, in high amounts, is harmful to health and is considered to lack environmental compatibility. In some cases, there may be requirements to identify these compounds with hazard symbols.
Therefore, what is needed are water-soluble cellulose derivatives that are glyoxal-free, yet are readily dispersible and hydrate quickly in aqueous solutions, characterized by little to no lump formation and a relatively rapid viscosity build up over time.